One problem with current hand-held recoilless bazooka-type weapons when fired in tight spaces is the high sound pressure levels which are generated around the weapon as an effect of the expansion of the combustion gases and the reinforcing effect given by tight spaces. High sound pressure levels adversely affect the firer of the weapon, resulting, inter alia, in impaired firing capability. High sound pressure levels can also cause damage to the firer. One way of reducing the sound pressure is to cool the combustion gases.
Known solutions for cooling of combustion gases relate to rocket weapons in which the barrel is used as the combustion chamber, wherein a reservoir containing coolant is arranged behind the propellent powder charge in the barrel. A pressure increase in the barrel caused by the propellent powder charge leads to an explosive opening of the coolant reservoir, whereupon the coolant, usually water, mixes with the combustion gases more or less instantaneously.
The process takes place initially, during the first part of the combustion process, which means that further cooling during the later part of the combustion process is not possible.